1. Field
The example embodiments relate to a semiconductor memory device, and more particularly to an input circuit of a non-volatile semiconductor memory device, and a method of inputting data into a non-volatile semiconductor memory device.
2. Description of Related Art
A conventional non-volatile semiconductor memory device may use a low voltage complementary metal oxide semiconductor (LVCMOS) interface which may include a NOR gate, a NAND gate, or the like because a write-speed of the conventional non-volatile semiconductor memory device, for example, a flash memory device, may be relatively slow.
FIG. 1 is a circuit diagram illustrating an example of the input circuit of a conventional non-volatile semiconductor memory device.
Referring to FIG. 1, the input circuit may include an input buffer 10, a clock buffer 20, and a sampler 30. The input buffer 10 may include a NOR gate 11 and inverters 13, 15, and 17. The clock buffer 20 may include a NOR gate 21 and inverters 23, 25, and 27. The sampler 30 may include a D flip-flop 31 and inverters 33 and 35. The input buffer 10 may buffer an input signal IN in response to an enable signal EN. The clock buffer 20 may buffer a clock signal CLK in response to a clock enable signal CLK_EN. The sampler 30 may sample an output signal of the input buffer 10 in response to an output signal of the clock buffer 20, and may generate a buffer output signal BOUT.
The conventional non-volatile semiconductor memory device may convert the input signal to a complementary metal oxide semiconductor (CMOS) signal that may be used in an internal circuit by using LVCMOS interface circuit like, for example, the circuit illustrated in FIG. 1 because a write-speed of the conventional non-volatile semiconductor memory device may be relatively slow.
As speeds for transmitting an input signal on a system bus become faster, swing ranges and setup/hold margins of the input signal may become smaller. Accordingly the input signal may be buffered improperly in a conventional input circuit. Thus an input circuit that can buffer the input signal of a small swing range may be required.